<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Test mrow fallback for some MathML elements (preferred logical widths)</title>
<link rel="help" href="https://w3c.github.io/mathml-core/#script-and-limit-schemata">
<meta name="assert" content="Verify that invalid markup fallbacks to mrow behaviour when computing preferred logical widths.">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/mathml/support/feature-detection.js"></script>
<script src="/mathml/support/fonts.js"></script>
<script src="/mathml/support/layout-comparison.js"></script>
<script src="/mathml/support/mathml-fragments.js"></script>
<script src="/mathml/support/invalid-markup.js"></script>
<style>
  /* Revert style specified in the UA style sheet that changes box size. */
  mfrac { padding-inline: 0; }
</style>
<script>
  setup({ explicit_done: true });
  window.addEventListener("load", () => { loadAllFonts().then(runTests); });

  function wrapShrink(el) {
    let wrapper = document.createElement("div");
    let math = FragmentHelper.createElement("math");
    wrapper.style.display = "inline-block";
    math.appendChild(el);
    wrapper.appendChild(math);
    return wrapper;
  }

  function runTests() {
    let container = document.getElementById("container");
    let invalidMarkup = generateInvalidMarkup();
    const epsilon = 1;

    for (let math of invalidMarkup.children) {
      let element = math.firstElementChild;
      let reference = element.nextElementSibling;
      let description = element.dataset.description;

      // generateInvalidMarkup() puts both the element and the reference in the same <math>.
      // To test preferred logical widths, we need to separate them out under different divs.
      let elementWrapper = wrapShrink(element);
      let referenceWrapper = wrapShrink(reference);
      container.append(elementWrapper, referenceWrapper);
      test(function() {
        assert_approx_equals(elementWrapper.getBoundingClientRect().width, referenceWrapper.getBoundingClientRect().width, epsilon);
      }, `Invalid <${element.tagName}> should fallback to mrow behaviour when computing preferred logical widths (${description})`);
    }

    done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <div id="container"></div>
</body>
</html>
